Rising out of the Sarcidano plain, about 10km south of Orroli and off the SP10, is the Nuraghe Arrubiu, which takes its Sardinian name from the red colour of the trachyte stone. This impressive structure, centred on a robust tower, now about 16m high, is thought to have once reached 30m. Surrounding it is a five-tower defensive perimeter and the remains of an outer wall and settlement. The artefacts found here indicate that the Romans made good use of it.